Table 2.
Results of 20 patients with cancer of unknown primary tumors.
| Patient no. | Sex | Age | Site of metastases | Pathology | PET or PET/CT |
PET or PET/CT finding | Primary site detected by IHC |
IHC markers used to detect primary site |
|||
|---|---|---|---|---|---|---|---|---|---|---|---|
| Primary tumor | Known metastases | Additional findings | Results of additional findings |
||||||||
| 1 | M | 54 | Cervical LN | Squamous cell ca. | PET | not seen | seen | - | - | - | - |
| 2 | F | 66 | Bone | PD | PET/CT | not seen | seen | - | - | - | Vimentin, CK 7, CK 20, CD 68 |
| 3 | M | 55 | Cervical LN | PD | PET→PET/CT | not seen | seen | - | - | - | CK 7, CK 19, CK 20, Thyroglobulin, |
| 4 | F | 57 | Bone | Signet ring cell ca. | PET/CT | not seen | seen | Neck, thyroid, hand, forearm uptake | Benign | - | CK 7, CK 20, TTF-1, ER, PR |
| 5 | M | 56 | Skin | Adenocarcinoma | PET→PET/CT | not seen | not seen | Mid-esophagus uptake (subcarinal LN) | Benign | - | CK 7, CK 19, CK 20 TTF-1 |
| 6 | F | 36 | Bone | Adenocarcinoma | PET | not seen | seen | - | - | Breast | ER, PR, C-erbB2, CK 7, CK 20, TTF-1, GCDFP-15 |
| 7 | F | 62 | Abdominal LN | PD | PET/CT | not seen | seen | Pharynx, thyroid, uptake | Benign | - | - |
| 8 | M | 15 | Cervical LN | PD | PET | not seen | seen | - | - | - | CK, Vimentin, CD 68 |
| 9 | M | 54 | Cervical LN | Squamous cell ca. | PET/CT | not seen | seen | - | - | - | - |
| 10 | M | 46 | Brain | Leiomyosarcoma | PET→PET/CT | not seen | seen | Left lower lung uptake | Benign | - | CD 34, Smooth muscle actin, CD 68 |
| 11 | F | 34 | Cervical LN | PD | PET | not seen | seen | - | - | Lung | CK 7, CK 20, TTF-1 |
| 12 | F | 60 | Omentum | Adenocarcinoma | PET/CT | not seen | * | * | * | - | CK7, CK 20 |
| 13 | F | 48 | Peritoneum | Adenocarcinoma | PET/CT | not seen | seen | Inguinal LN uptake | Malignant | - | CK7, CK 20 |
| 14 | F | 60 | Axillary LN | PD | PET | not seen | seen | - | - | - | CK 7, CK 20, TTF-1 |
| 15 | M | 61 | Cervical LN | PD | PET→PET/CT | not seen | seen | - | - | - | CK, leukocyte common antigen |
| 16 | F | 53 | Ureter | PD | PET/CT | not seen | * | * | * | - | CK 7, CK 20 |
| 17 | M | 59 | Abdominal LN | Adenocarcinoma | PET/CT | not seen | seen | Thyroid uptake | Benign | - | CK 7, CK 19, CK 20, TTF-1 |
| 18 | M | 68 | Abdominal LN | PD | PET | not seen | * | * | * | - | CD 56, CK |
| 19 | F | 51 | Axillary LN | PD | PET/CT | not seen | seen | - | - | - | CK 7, CK 20, TTF-1 |
| 20 | F | 43 | Bone | PD | PET | not seen | seen | Neck LN uptake | Malignant | - | CK 7, CK 20 |
*PET or PET/CT was done several months later at the time of the initial workup.
Abbreviation: LN = lymph node., ca. = carcinoma, PD = poorly differentiated carcinoma, CT = computed tomography, PET = positron-emission tomography, IHC = immunohistochemistry, ER = estrogen- receptor, PR = progesterone- receptor, CK = cytokeratin, TTF-1 = thyroid transcription factor-1, GCDFP-15 = gross cystic disease